In current practice, communications devices are used with many different types of dipoles, biconical dipoles, conical monopoles and discone antennas. These antennas, however, are sometimes large and include impractical shapes for a specific application.
Horn antennas are very popular at UHF (300 MHz-3 GHz) and higher frequencies. They often have a directional radiation pattern with a high gain, which can range up to 25 dB in some cases, with 10-20 dB being typical. Horn antennas have a wide impedance bandwidth. The bandwidth for practical horn antennas can be on the order of 20:1 (e.g. operating from 1 GHz-20 GHz), with a 10:1 bandwidth not being uncommon.
The gain of horn antennas often increases (and the beamwidth decreases) as the frequency of operation is increased. This is because the size of the horn aperture is measured in wavelengths. Horn antennas have very little loss, so the directivity of a horn is roughly equal to its gain.
U.S. Pat. No. 4,571,593 to Martinson entitled “Horn antenna and mixer construction for microwave radar detectors” is directed to a horn antenna, for use in microwave radar detector circuits, that comprises a molded horn element that is open at its bottom side, with a ridge molded into its flared top surface, and being electrically conductive at least at microwave frequencies such as in the X-band and K-band. The open bottom of the horn element mates to a conductive upper surface on a mounting board, and the horn is drawn down onto the mounting board so that its upper surface forms the bottom of the horn. Thus, the ridge is brought into physical and electrical contact with a feed strip formed in a microstrip board on the mounting board, that has a mixing diode or diodes associated therewith. By this construction, there is a positive and dimensionally stable association of the throat of the horn and the ridge to the feed strip and the mixing diode(s), without the necessity of any solder, inserted connectors or mounting pins, or the provision of any tuning posts or screws.
U.S. Pat. No. 7,835,600 to Yap, et al. entitled “Microwave receiver front-end assembly and array” is directed to a method of and apparatus for modulating an optical carrier by an incident electromagnetic field. The electromagnetic field propagates in a dielectric-filled transverse electromagnetic waveguide, At least one slice of an electro-optic material is disposed in the dielectric-filled transverse electromagnetic waveguide, the electro-optic material in the dielectric-filled transverse electromagnetic waveguide having at least one optical waveguide therein which has at least a major portion thereof guiding light in a direction orthogonal with respect to a direction in which the dielectric-filled transverse electromagnetic waveguide guides the incident electromagnetic field.
Phased array antennas typically have high size, weight and power (SWaP) and cost issues. Such high cost limits conventional phased arrays to high end applications. A typical brick array architecture provides high bandwidth and dense element spacing but is complicated and heavy. A conventional tile array architecture can use a lower cost printed circuit board approach and is lighter than the brick architecture, but it has less packaging volume for electronics, including power, control and the RF beamformer. Such tile arrays also typically require weight to be added to improve stiffness, e.g. to oppose vibrations etc.
Reducing the size, weight and cost of a horn antenna is desired. Providing a lightweight phased array is also desired.